Sewing machine for elastic seams



Dec. 19, 1950 H, DIAMOND 2,534,701

SEWING MACHINE FOR ELASTIC SEAMS Filed Feb. 5, 1949 5 Sheets-Sheet I.

HARR Y DIAMOND INVENTOR BMW ATTORNEY FIG! Dec. 19, 1950 H. DIAMOND SEWING MACHINE FOR ELASTIC SEAMS -s Sheet s-Sheet 2 Filed Feb. 5. 1949 INVENTOR BYWM ATTORNEY K9 v HARRY DIAMQND M Dec. 19, 1950 H. MMOND 2,534,701

SEWIRG MACHINE FOR ELASTIC SEAMS Filed Feb. 5, 1949 5 Sheets-Sheet 3 HARRY DIAMOND INVENTOR BYWM ATTORNEY Dwd R9,, 1950 .H. DIAMOND 5 3 1 SEWING MACHINE FORELTASTIC SEAMS Filed Feb. 5, 1949 5 sheeis sheet 4 HARRY DIAMOND INVENTOR Fl MW M- ATTO R N EY Dec. 19,, 1-950 H. DIAMOND 2,534,701

55mm mcumn FOR ELASTIC BEAMS Filed Feb. 5, 1949 5 Shee ts- Sheet 5 HA RR Y DIAMOND BNVENTOR ATTORNEY Patented Dec. 19, 1950 T QFFICE 11 Claims.

This invention relates to improvements in sewing machines, and more particularly to a mechanism for stitching elastic seams having an elastic thread cross-stitch throughout the entire length of the seams, the seams bein fully disclosed in my Patent No. 2,141,239, dated December 27, 1988.

The main object of this invention is to provide a cross-thread laying mechanism comprising an auxiliary feeding mechanism for positively and uniformly feeding an elastic thread in timed relation with the main feeding mechanism of the sewing machine to insure the formation of a perfect elastic seam.

Another object of this invention is to provide a pair of cooperating tapering feed rollers, one of which is driven by the needle-bar shaft and forming the auxiliary feeding mechanism, and to provide an elongated guide for preventing any Whipping motions of the elastic thread between the auxiliary and the main feeding mechanisms.

Another object of this invention is to provide means for shifting the elastic thread axially of the tapering rollers for adjusting the rate of speed of the elastic thread to equal the predetermined rate of speed of the main feeding mechanism for preventing stretching of the elastic thread.

Another object of this invention is to provide a cross-thread laying hook carrier slidably mounted on the presser-foot and in right-angular relation with the line of seam formation and reciprocated due to the motion of the needlebar shaft during all u and down positions of the presser-foot under operating conditions.

With the above and other objects in view, the invent on will be hereinafter more particularly described, and the combination and arrangement of parts will be shown in the accompanying drawings and pointed out in the claims which form x part of this specification.

Reference will now be had to the drawings, wherein like numerals of reference designate corresponding parts'throughout the several views, in which:

Figure 1 is a front view of a standard sewing machine equipped with my invention.

Figure 2 is a rear view of the machine.

Figure 3 is a top plan view of the machine showing the elastic thread feeding mechanism. Figure 4 is an end elevation of the machine. Figure 5 is a cross-sectional view taken on line --5 in Figure 1.

Figure 6 is a plan view of an enlarged frag mentary portion of two adjoining Panels of a garment showing an elastic seam comprising an elastic cross-stitch.

In the illustrated embodiment of the invention the numeral I'll indicates the work supporting base of a sewing machine to which my invention is applied. The sewing machine comprises an overhanging arm consisting of the upright portion H and overhanging portion l2. The sewing machine has stitch forming mechanism, including a presser-foot bar It, and needle-bar it, carried by the overhangin portion l2. The presser-foot bar has the usual spring for apply.- ing pressure.

The n edle-bar It is fitted with two laterally spaced needles l5, so that both sides of a com-. plete elastic lock stitch seam may be sewed in a garment at the same time. A two-piece pressere foot i6 is suitably secured to the presser-foot bar. The sewing machine has a needle feed wherein the needles I5 move with the feed dog 11 defining the main feeding mechanism.

Cooperating with the needles l5 above the work supporting base It, is a cross-thread laying mechanism consisting of a fixed guide for an 'i elastic thread 2! and a thread hook 22 which moves across the line of feed, The thread hook 22 engages the elastic thread 2! passing through the thread guide 20 and forms loops for the entrance of the needles.

The cross thread joins the needle threads on the upper face of the fabric. Cooperating with the needles beneath the work support is a suitable looper (not shown), which connects the needle threads beneath the fabric sections worked upon.

A guideway is fixed to the rearward face of the presser-foot body 25. The guideway 24 is of square crossesection. An elongated carrier 25 of square cross-section is slidably mounted in the guideway 24 in non-rotatable relation therewith. An upright pin 2'! is suitably fixed in the slide member 26 and has a dog 28, vertically adjustable thereon by a screw 29.-

The cross-thread laying hook 22 is secured by a screw ii to the dog 28 and has an aperture 32 in a horizontal extension 33 thereof through which the elastic thread 2! is fed rearwardly in direction of the line of seam formation. A pin 35 extends reawardly from the carrier 26 and provides a pivot on which an arm 35 is mounted for oscillating motion, The arm 36 has an elongated horizontal extension 37 which terminates in a pivotal junction 38.

As best shown in Figure 2, a lever 40 is pivotalted on apin it! in a bracket 42. WbiQ is fixed to the over-hanging arm !2 by bolts 3- The lower end of the lever is in engagement with the junction 38.

As best shown in Figure 5, the actuating mechanism for the lever 46 of the cross-thread laying mechanism comprises the needle-bar shaft and a bevel gear 46 fixed thereon, and which engages with a bevel gear 4'! carried by a transverse shaft 48. The transverse shaft 48 has a gear 45 mounted thereon and which is in meshed relation with a larger gear 50 fixed to a shaft 5| in a housing 52 which forms part of the bracket 42.

The large gear 58 has an eccentric 55 adjustably mounted thereon. The upper portion of the lever 40 has a forked end 56 in engagement with the eccentric 55.

The eccentric 55 is integral with a slide block 58. The slide block 58 is mounted in a guideway 59 in a gear hub 68 which is fixed to an end of the shaft 5!. A screw 8| threaded in the slide block 58 is suitably arranged to cause a sliding motion of the eccentric 55 to or from the center of the shaft 5!. By adjusting the screw 6|, the throw of the lever 45, and the reciprocations of the thread hook 22 is varied.

Auxiliary feeding mechanism is provided for positively feeding the elastic thread 2! to the main feeding mechanism i1 and comprises a pair of cooperating feed rollers 65 and 61, the rollers being mounted with the smallest ends facing in opposite directions.

A bell-crank lever 1'6- is mounted on a pin H in a bracket extension 42 and carries the tapering roller 51, the exterior surface of which is made smooth. The roller 68 has serrations 72 cut therein all along its length.

A bracket 15 is suitably supported on the overhanging arm I 2 or in any other suitable manner, and carries a roll 68 of elastic thread 2! which passes over the forward portion of the lever 10, between the rollers 66 and 51, and passes into and through the elongated guide 29 and then through the aperture 32 in the thread finger 22. A coil spring Tl is mounted to exert upward pressure against the free end of the bell-crank lever in and causes the roller 61 to resiliently press against the roller 66.

When the shaft 5| rotates, the roller 66 rotates in feeding direction to feed the elastic thread to the main feeding mechanism H, the springpressed roller 61 coacts in the feeding operation.

A threading arm 18 is pivoted on a pin 19 in the bracket extension 42'. The pin 19 has gear mounted thereon and in meshed engagement with a worm 8! carried by a rotatable spindle 82. The threading arm 18 has a spring-closed aperture 83 through which the elastic thread 2i is threaded. The spindle 82 carries a gear 84. A leaf spring 85 suitably fixed below the gear 84 has an upward extension in pressure engagement with one of the teeth in the gear and retains the gear in set position.

By rotating the spindle 82 and the gear 84, the free end of the threading arm '58 swings in an arc and shifts the elastic thread 21 axially of the rollers and this adjusts the rate of speed of the elastic thread. This adjustment makes possible the feeding of the elastic thread through the auxiliary feeding mechanism 65 to equal the predetermined speed of the main feeding mechanism i! and prevents stretching of the elastic thread 2! during seam formation.

The elastic seam 89 made by the mei hanism herewith, is shown in Figure 6 and comprises two side edges of adjacent panels 90, 9B. The side edges are separately folded and stitched to form hens. The hemmed fabric is placed on the work supporting base it and guided by an upright central rib 92 to the needles l5 and stitched by two parallel rows of straight-line stitching 9|, Eli, using non-elastic threads. The raw edges of the fabric are concealed inside the folds. The parallel rows of non-elastic straight-line stitching are interlocked with a cross-stitch 93 using the elastic thread 2| which is positioned intermediate the fabric and the straight-line stitching.

The spaced rows of straight-line stitching serve for anchoring the cross-stitches to the fabric. The folded side edges of the panels 9% lie flat in a single plane and so that the seam has no undue bulkiness. The hems face in opposite directions.

It will be noted that the hemmed fabric edges are normally in adjoining or abutting relation and so that when the two sections of fabric are stretched. transversely, the side edges of the panels will be temporarily pulled apart and provide a linear opening for ventilation but will immediately close back to the normal adjoining relation when the distending stresses are relieved.

The length of each of the cross-threads is substantially the same as the distance between the two rows of straight-line stitching so as to normally connect and hold the folded edges in flat and abutting relation and prevent the edges from being spaced apart or from being in overlapping relation. In Figure 6, the straight-line stitching forming the two hems is not shown.

It is to be noted that the diameter of the gear 58 is twice as large as the diameter of the gear 49 and this speed reducing ratio causes two I stitches to be formed by each of the needles [5 for each motion of the cross-thread laying hook 22.

In accordance with the patent statutes I have described and illustrated the preferred embodiment of my invention, but it will be understood that various changes and modifications can be made therein without departing from the spirit of the invention as defined by the appended claims.

I claim:

1. In combination with a sewing machine having a main feeding mechanism and a presserfoot and a shaft mounted in an upper arm of said sewing machine and transverse with the needle-bar shaft, said needle-bar shaft having gear means mounted thereon and being intermeshed with gear means mounted on said transverse shaft for driving said shaft, said transverse shaft having further gear means operated thereby, said further gear means including an eccentric, a cross-thread laying hook carrier slidably mounted on said presser-foot in right-angular relation with the line of seam formation, said carrier having a horizontal extension above said work supporting base and terminating in a forked end portion, a lever having its upper end in engagement with said eccentric, the lower end of said lever being in engagement with said forked end portion, whereby said cross-thread laying hook is constrained to reciprocate solely due to the motion of said needle-bar shaft, said forked junction permitting said reciprocating motions of said cross-thread laying hook during all up and down positions of said presser-foot under operating conditions, auxiliary feeding means on means for shifting said elastic thread axially of said rollers for adjusting the rateof speed of said threadto equal the predetermined speed of said main feeding mechanism for preventing stretching'of said elastic thread during seam formation.

2'. In combination with a sewing machine hav ing a main feeding mechanism and a presser-foot anda shaft mounted in an upper arm of said sewing machine and transverse with the needlebar shaft, said needle-bar shaft having gear means mounted thereon and being intermeshed with gear means mounted on said transver shaft for driving said shaft, said transverse shaft having speed reducing gear means operated thereby, said speed reducing gear means including an eccentric, a cross-thread laying hook can rier slidably mounted on said presser-foot in right-angular relation with the line of scam formation, said carrier having a horizontal ex 11- sion above said work supporting base and terminating in a junction permitting up and down movements, a. lever having its upper end in engagement' with said eccentric, the lower end of said lever being in engagement with said junction, said junction permitting said reciprocating motions of said cross-thread laying hook during all up and down positions of said presser-foot, whereby said cross-thread laying hook is con strained to reciprocate due to the motion of said needle-bar shaft, auxiliary feeding means on said upper arm for positively feeding elastic thread 4.:

to said main feeding mechanism comprising pair of cooperating tapering feed rollers, yielding means for urging one of said rollers toward the other roller, means connected to said. nee dle-bar shaft for rotating one of said rollers in feeding direction at a rate of speed equal to the rate of speed of said main feeding mechanism, an elastic thread passing between said rollers and means for shifting said elastic thread axially of said rollers for adjusting the rate of speed 01 said 1 thread to equal the predetermined speed of said main feeding mechanism for preventing stretching, of said elastic thread during seam formation.

3'. In combination with a sewing machine having a main feeding mechanism below a work supporting base and a presser-foot, and a shaft mounted in an upper arm of said sewing machine and transverse with the needle-bar shaft; said needle-bar shaft having gear means mounted tion, said junction permitting reciprocating motions of said cross thread laying hook during all up and down. positions of said presser-foot, said cross-thread laying hook being constrained. tov

said said.

reciprocate due to the" motion ofi said. needle-bar: shaft, auxiliary: feeding; means on' said-upper arn'rv for positively feeding elastic thread tosaid-main:

an. elastic thread passing between said rollers,

and'means for shifting said elastic thread axially of said rollers for adjusting the rateof speed of said thread to equal the predetermined speed-of said main feeding mechanism for preventing stretching of said elastic threadv during. seam f or.

mation.

i. In combination witha sewing machine hav ing a main feeding mechanism below a. work supporting base and presser-foot, and. a shaft mounted in anupper arm of said sewing machine and transverse with. the needle-bar shaft; said needledoar shaft having gear means mounted thereon andv being intermeshed withgear. means mounted onsaid transverse shaft for drivingsaid shaft, said transverse shaft having speed reduc-v ing'gear means and aneccentric operated thereby, a cross-thread laying hook carrier slidably mounted on said presser-foot in right-angular relation with the line of seam formation, said carrier having a horizontal extension above said work supporting base and terminating in apivotal. junction, a lever fulcrumed. in said upper arm and. having its upper end in engagement with said; eccentridthe lower endof said, lever being in engagement withsaidjunction, meansfor ad.- justing said eccentric, said junction permitting reciprocating motions of said cross-thread: laying-hook during allup-anddown positions of said. pl'esser foot, said cross-thread laying, hook. being constrained to reciprocate due to the motion of said needle-bar shaft, auxiliary feedingmeans on said upper arm for positively feeding. elastic thread to said main feeding: mechanism comprising a pair of cooperating tapering feed rollers,

yielding means for urging one of said rollers toward the. other roller, means operatively connected. with saidneedle-bar shaftfor rotating one of; saidrollers in feeding direction, an elastic. thread passing between, said rollers, means for guiding said elastic thread between said auxiliary and said main feeding mechanism, and means-for shifting'said" elastic thread axially of said rollers. for adjusting, therate of speed of said thread to equal the predetermined speed of saidmainfeeding mechanism for preventing stretching of said elastic threadduring seam formation.

5. In combination with a sewing machine.hav-- inga main feeding mechanism below. a work supporting base and a presser-foot, and a shaft mounted in-an upper arm of said sewingma-chinev and transverse with the needle-bar shaft; saidv needle-bar shaft. having gear means mounted thereon and; beingintermeshed with. gear means 1 mountedon saidtransverse shaft for driving said.

shaft, an eccentric operatively associated with-v said transverse shaft, a cross-thread laying hook carrier. slidably mounted on said presser-foot in right-angular relation with the line of scam for.- mation, said carrier having a horizontal extension above said work supporting base and terminating in. a pivotal junction, a lever fulcrumedin said upper arm and having its upper end. in engagement with said eccentric, thelower end. of said lever being. in. engagement-with said junction, means for adjusting said eccentric, said junction permitting reciprocating motions of said cross-thread laying hook during all up and down positions of said presser-foot, said cross-thread laying hook being constrained to reciprocate due to the motion of said needle-bar shaft, auxiliary feeding means on said upper arm for positively feeding elastic thread to said main feeding mechanism comprising a pair of cooperating tapering feed rollers, said rollers being mounted with the smallest ends facing in opposite directions, yielding means for urging one of said rollers toward the other roller, means operatively connected with said needle-bar shaft for rotating one of said rollers in feeding direction, an elastic thread passing between said rollers, means for guiding said elastic thread between said auxiliary and i said main feeding mechanism, and means for shifting said elastic thread axially of said rollers for adjusting the rate of speed of said thread to equal the predetermined speed of said main feeding mechanism for preventing stretching of said elastic thread during seam formation.

6. In combination with a sewing machine having a main feeding mechanism below a work supporting base and a presser-foot, and a shaft mounted in an upper arm of said sewing machine and transverse with the needle-bar shaft; said needle-bar shaft having gear means mounted thereon and being intermeshed with gear means mounted on said transverse shaft for driving said shaft, an eccentric operatively associated with said transverse shaft, a guideway carried by said presser-foot, a cross-thread laying hook carrier slidably mounted in said Presser-foot guideway in right-angular relation with the line of seam formation, said carrier having a hori zontal extension pivotally mounted thereon and terminating in a pivotal junction, a lever fulcrumed in said upper arm and having its uper end in engagement with said eccentric, the lower end of said lever being in engagement with said pivotal junction, means for adjusting said eccentric, said pivotall mounted extension and said junction permitting reciprocating motions of said cross-thread laying hook during all up and down positions of said presser-foot, said cross-thread laying hook being constrained to reciprocate due to the motion of said needle-bar shaft, auxiliary feeding means on said upper arm for positively feeding elastic thread to said main feeding mechanism comprising a pair of cooperating tapering feed rollers, said rollers being mounted with the smallest ends facing in opposite directions, yielding means for urging one of said rollers toward the other roller, means operatively connected with said needle-bar shaft for rotating one of said rollers in feeding direction, means for supporting an elastic thread for passage between said rollers, means for guiding said elastic thread between said auxiliary and said main feeding mechanism, and means for shifting said elastic thread axially of said rollers for adjusting the rate of speed of said thread to equal the predetermined speed of said main feeding mechanism for preventing stretching of said elastic thread during seam formation.

'7. A mechanism for producing elastic seams, comprisin in combination with a sewing machine having a ma n feeding mechanism below a work supporting base and a presser-foot, and a shaft mounted in an upper arm of said sewing machine and transverse with the needle-bar shaft; said needle-bar shaft having gear means mounted thereon and being intermeshed with gear means mounted on said transverse shaft for driving said shaft, an eccentric operatively associated with said transverse shaft, a guideway carried by said presser-foot, a cross-thread laying hook carrier slidably mounted in said presser-foot guideway, said carrier having a horizontal extension pivotally mounted thereon and terminating in a pivotal junction, a. lever fulcrumed in said upper arm and having its upper end in engagement with said eccentric, the lower end of said lever being in engagement with said pivotal junction, means for adjusting said eccentric, said pivotally mounted extension and said junction permitting reciproeating motions of said cross-thread laying hook during up and down positions of said presser-foot, said cross-thread laying hook being constrained to reciprocate due to the motion of said needlebar shaft, auxiliary feeding means on said upper arm for positively feeding elastic thread to said main feeding mechanism comprfsing a pair of cooperating tapering feed rollers, said rollers being mounted with the smallest ends facing in opposite directions, yielding means for urging one of said rollers toward the other roller, means operatively connected with said needle-bar shaft for rotating one of said rollers in feeding direction, means for supporting an elastic thread forpassage between said rollers, tubular means for guiding said elastic thrcad between said auxiliary and said mafn feeding mechanism, and means for shifting said elastic thread axially of said rollers for adjusting the rate of speed of said elastic thread to equal the predetermined speed of said main feeding mechanism for preventing stretching of said elastic thread during seam formation.

8. A mechanism for producing elastic seams, comprising in combination with a sewing machine having a main feeding mechanism below a work supporting base and a presser-foot and an upper arm supporting a needle bar shaft; a shaft mounted in said upper arm and transverse with said needle-bar shaft, said needle-bar shaft hav ing gear means mounted thereon and being intermeshed with gear means mounted on said transverse shaft for driving said shaft, an eccentric operatively associated with said transverse shaft, a guideway carried by said presser-foot, a crossthread laying hook carrier slidably mounted in said presser-foot guideway, a lever fulcrumed in said upper arm and having its upper end in engagement wLth said eccentric, means connecting the lower end of said lever with said carrier, auxiliary feeding means on said upper arm for positively feeding elastic thread to said main feeding mechanism comprising a pair of cooperating tapering feed rollers, said rollers being mounted with the smallest ends facing in opposite directlons, yield'ng means for urging one of said rollers toward the other roller, means operatively connected with said needle-bar shaft for rotating one of said rollers in feeding direction, means for supporting an elastic thread for passage between said rollers, means for guiding said elastic thread between said auxiliary and said main feeding mechanism, and means for shifting said elastic thread axially of said rollers for adjust'ng the rate of speed of said elastic thread to equal the predetermined speed of said main feeding mechanism for preventing stretching of said elastic thread during seam formation.

9. A mechanism for producing elastic seams, comprising in combination with a sewing machine having a main feeding mechanism below a work supporting base and a presser-foot and an upper arm supporting a needle-bar shaft; a shaft mounted transversely with said needle-bar shaft, said needle-bar shaft having gear means mounted thereon and being intermeshed with gear means mounted on said transverse shaft for driving said shaft, an eccentric operatively associated with said transverse shaft, a guideway carried by said presser-foot, a cross-thread laying hook carrier slidably mounted in said presser-foot guideway, a lever fulcrumed in said upper arm and having its upper end in engagement with said eccentric, means connecting the lower end of said lever with said carrier, auxiliary feeding means for posi tively feeding elastic thread to said main feeding mechanism comprising a pair of cooperating tapering feed rollers, said rollers being mounted with the smallest ends facing in opposite directions, yielding means for urging one of said rollers toward the other roller, means operatively connected with said needle-bar shaft for rotating one of said rollers in feeding direction, means for guiding an elastic thread between said auxiliary and said main feeding mechanism, and means for shifting said elastic thread axially of said rollers for adjusting the rate of speed of said elastic thread to equal the predetermined speed of said main feedin mechanism for preventing stretching of said elastic thread during seam formation.

10. A mechanism for producing elastic seams, comprising in combination with a sewing machine having a main feeding mechanism below a work supporting base and a presser-foot and an upper arm supporting a needle-bar shaft; a shaft mounted transversely with said needle-bar shaft, said needle-bar shaft having gear means mounted thereon and being intermeshed with gear means mounted on said transverse shaft for driving said shaft, an eccentric operatively associated with said transverse shaft, a guideway carried by said presser-foot, a cross-thread laying hook carrier slidably mounted in said presser-foot guideway, a lever fulcrumed in said upper arm and having its upper end in engagement with said eccentric, means connecting the lower end of said lever with said carrier, auxiliary feeding means for feeding elastic thread to said main feeding mechanism comprising a pair of cooperating tapering feed rollers, yielding means for urging one of said rollers toward the other roller, means for rotating one of said rollers in feeding direction, means for guidin an elastic thread between said auxiliary feeding means and said main feeding mechanism, and means for shifting said elastic thread axially of said rollers for adjusting the rate of speed of said elastic thread to equal the predetermined speed of said main feeding mechanism for preventing stretching of said elastic thread during seam formation.

11. A mechanism for producing elastic seams, comprising in combination with a sewing machine having a main feeding mechanism and a presserfoot and an arm supporting a needle-bar shaft; a shaft mounted transversely with said needlebar shaft, said needle-bar shaft having gear means mounted thereon and intermeshed with gear means mounted on said transverse shaft, an eccentric operatively associated with said transverse shaft, a guideway carried by said presserfoot, 2, cross-thread laying hook carrier slidably mounted in said guideway, a lever having one end in engagement with said eccentric, means connecting the other end of said lever with said carrier, auxiliary feeding means for feeding elastic thread to said main feeding mechanism, means for guiding an elastic thread from said auxiliary feeding means to said main feeding mechanism, and means for adjustin the rate of speed of said elastic thread to equal the predetermined speed of said main feeding mechanism for preventing stretching of said elastic thread during seam formation.

HARRY DIAMOND.

No references cited. 

